<div style="clear:both;"></div>
<div id="footer">
    <div id="siteinfo">
    </div><!-- #siteinfo -->
</div>
</div>
<script>
    $(document).ready(function(){
        var hH = $("#header").innerHeight();
        var fH = $("#footer").innerHeight();
        var windowH = $(document).height();
        $("#main").height(windowH-hH-fH-32);
    });
</script>
</body>
</html>